1. Field of the Invention
This invention relates to a deodorizing lamp and a method for the production thereof. More particularly, this invention relates to a deodorizing lamp which cleans air by decomposing malodorous substances in the air, operates safely, and retains its ability to decompose malodorous substances for a long time, and a method for the production of the deodorizing lamp.
2. Description of the Prior Art
When a semiconductor is exposed to light, it produces electrons that exert a strong reducing action and positive holes that exert a strong oxidizing action. It thus decomposes compounds which happen to come in contact with it by oxidation and reduction. This photocatalytic action of the semiconductor can be harnessed for easily decomposing and removing malodorous substances in the air. One example of a device utilizing the photocatalytic action of a semiconductor for removing malodorous substances by decomposition consists of a fluorescent lamp having a cover lined with a semiconductor ["Industrial Materials", Vol. 41, No. 1, p. 10 (1993)]. This fluorescent lamp admits air through a gap in the cover, allows the incoming air to contact the semiconductor, and frees the air of malodorous substances by decomposing the substances by the oxidizing and reducing actions of the electrons and positive holes produced in the semiconductor by the light from the fluorescent lamp.
With this device, however, flies, mosquitoes, moths and other small insects enter the interior of the fluorescent lamp through the gap formed in the cover, collect inside the cover, and eventually foul the inside of the cover to the point of blocking the incident light from passing through the cover. Thus, this device experiences a serious decline in its ability to remove malodorous substances by decomposition. To prevent this trouble, the interior of the cover of the fluorescent lamp must be cleaned frequently. Thus, there is a need to develop a deodorizing device which requires no cleaning after it has been installed and which retains its ability to decompose malodorous substances for a long time.